Despite the advances in search technology, searching remains an often-onerous task. For example, searches tend to be iterative, because initial rounds of searching are performed to identify search terms that may be used in subsequent rounds of searching. Searchers do not initially know if there are helpful search terms they do not know. The effectiveness of a search may be limited by the existence of variants of a term. Evaluating search results is onerous, often requiring review of entire documents.
An example of a difficult type of searching is patent searching. A searcher may not know the best technical terms to use in a patent search. Different patents or patent applications may use different terms, or variants of the same term, to refer to the same or similar ideas or entities. To evaluate the relevance of the results of a patent search, the searcher often has to manually review dense sections of the patent or patent application, such as the claims and detailed description.